Treatment Of Polycythemia Vera Research Articles

Diagnosis and Treatment of Polycythemia Vera

ImportancePolycythemia vera (PV), a myeloproliferative neoplasm characterized by an increased red blood cell mass and increased risk of thrombosis, affects approximately 65 000 people in the US, with an annual incidence of 0.5 to 4.0 cases per 100 000 persons.ObservationsErythrocytosis (hemoglobin >16.5 mg/dL in men or >16.0 mg/dL in women) is a required diagnostic criterion, although thrombocytosis (53%) and leukocytosis (49%) are common. Patients may have pruritus (33%), erythromelalgia (5.3%), transient visual changes (14%), and splenomegaly (36%) with abdominal discomfort. More than 95% of patients have a JAK2 gene variant, which helps distinguish PV from secondary causes of erythrocytosis, such as tobacco smoking or sleep apnea. Among 7 cohorts (1545 individuals), the median survival from diagnosis was 14.1 to 27.6 years. Prior to or at the time of PV diagnosis, arterial thrombosis occurred in 16% of patients and 7% had venous thrombotic events, which could involve unusual sites, such as splanchnic veins. PV is also associated with an increased bleeding risk, especially in patients with acquired von Willebrand disease, which can occur with extreme thrombocytosis (platelet count, ≥1000 × 109/L). All patients with PV should receive therapeutic phlebotomy (goal hematocrit, <45%) and low-dose aspirin (if no contraindications). Patients who are at higher risk of thrombosis include those aged 60 years or older or with a prior thrombosis. These patients and those with persistent PV symptoms may benefit from cytoreductive therapy with hydroxyurea or interferon to lower thrombosis risk and decrease symptoms. Ruxolitinib is a Janus kinase inhibitor that can alleviate pruritus and decrease splenomegaly in patients who are intolerant of or resistant to hydroxyurea. About 12.7% of patients with PV develop myelofibrosis and 6.8% develop acute myeloid leukemia.Conclusions and RelevancePV is a myeloproliferative neoplasm characterized by erythrocytosis and is almost universally associated with a JAK2 gene variant. PV is associated with an increased risk of arterial and venous thrombosis, hemorrhage, myelofibrosis, and acute myeloid leukemia. To decrease the risk of thrombosis, all patients with PV should be treated with aspirin and therapeutic phlebotomy to maintain a hematocrit of less than 45%. Cytoreductive therapies, such as hydroxyurea or interferon, are recommended for patients at high risk of thrombosis.

Pharmacokinetics and Pharmacodynamics of Rusfertide, a Hepcidin Mimetic, Following Subcutaneous Administration of a Lyophilized Powder Formulation in Healthy Volunteers.

Hepcidin, an endogenous peptide hormone, binds to ferroportin and is the master regulator of iron trafficking. Rusfertide, a synthetic peptide, is a potent hepcidin mimetic. Clinical studies suggest rusfertide may be effective in the treatment of polycythemia vera. This study investigated the dose-ranging pharmacokinetics, pharmacodynamics, and safety of a lyophilized formulation of rusfertide. A randomized open-label crossover study was conducted in two groups of healthy adult subjects to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of subcutaneous rusfertide doses that ranged from 10 to 60 mg of a lyophilized formulation and 20 mg of an aqueous prefilled syringe formulation that were used in clinical trials. Rusfertide showed a rapid initial absorption. Median time to peak plasma concentrations for the lyophilized formulation was 24h for doses of 10-30 mg and 2-4 h for doses of 45 and 60 mg. Mean terminal half-life ranged from 19.6 to 57.1 h. Rusfertide peak concentration and area under the concentration-time curve increased with an increasing dose, but in a less than dose-proportional manner. Metabolites M4 and M9 were identified as major metabolites. At the rusfertide 20-mg dose, the lyophilized formulation had an area under the concentration-time curve from time zero to infinity approximately 1.5-fold higher than the aqueous formulation. The elimination half-life was comparable for the two formulations. Dose-related decreases in serum iron and transferrin-iron saturation were seen following rusfertide treatment. The majority of treatment-emergent adverse events were mild; treatment-related treatment-emergent adverse events seen in ≥10% of subjects were injection-site erythema and injection-site pruritus. Rusfertide was well tolerated; the pharmacokinetic and pharmacodynamic results indicate that lyophilized rusfertide is suitable for once-weekly or twice-weekly administration.

Ethnic sensitivity analyses of pharmacokinetics, efficacy and safety in polycythemia vera treatment with ropeginterferon alfa-2b.

Ropeginterferon alfa-2b (Ropeg) is approved for the treatment of adults with polycythemia vera (PV). This report aims to analyze the ethnic sensitivity of Ropeg for the treatment of PV, comparing the pharmacokinetics (PK), efficacy, and safety profiles across diverse ethnic groups. We conducted a relevant review of PV and analysis of data obtained from clinical studies involving Ropeg. The PK behavior of ropeg showed no significant differences between Chinese and overseas populations. Their efficacy and safety profiles were similar across the ethnic groups. The analyses indicated that the dose-exposure-response profile of Ropeg was consistent irrespective of ethnic variations. The results suggest that Ropeg exhibits a consistent PK and pharmacodynamics profile and a similar therapeutic effect across different ethnic groups, confirming its efficacy and safety in the global treatment of PV. More generally, these findings support the broader application of Ropeg in diverse patient populations and emphasize the need for an inclusive clinical practice.

Current status of hydroxyurea in treatment of polycythemia vera

Current status of hydroxyurea in treatment of polycythemia vera

How we treat polycythemia vera

Polycythemia vera is a disease known since ancient times, however, until recent decades, diagnosis was carried out by exclusion, and therapy was symptomatic. The discovery of the pathogenetic role of mutations in the Janus kinase II gene has led to the possibility of establishing a diagnosis based not only on morphology, but also on genetic verification and to the development of directed targeted therapy, which is much more effective than previously used methods. The introduction of molecular genetic screening led to the need for a differential diagnosis with familial erythrocytosis, and the lessons of the coronavirus pandemic revealed the presence in the population of a significant proportion of patients with erythrocytosis due to the carriage of gene polymorphisms associated with familial hemochromatosis. The article presents our own personalized algorithms for the diagnosis and treatment of polycythemia vera and the results of their use, demonstrating the possibility of a two-fold reduction in the incidence of thrombosis and an increase in overall survival.

Interferons in the treatment of myeloproliferative neoplasms.

Interferons are cytokines with immunomodulatory properties and disease-modifying effects that have been used to treat myeloproliferative neoplasms (MPNs) for more than 35 years. The initial use of interferons was limited due to difficulties with administration and a significant toxicity profile. Many of these shortcomings were addressed by covalently binding polyethylene glycol to the interferon structure, which increases the stability, prolongs activity, and reduces immunogenicity of the molecule. In the current therapeutic landscape, pegylated interferons are recommended for use in the treatment of polycythemia vera, essential thrombocythemia, and primary myelofibrosis. We review recent efficacy, molecular response, and safety data for the two available pegylated interferons, peginterferon alfa-2a (Pegasys) and ropeginterferon alfa-2b-njft (BESREMi). The practical management of interferon-based therapies is discussed, along with our opinions on whether to and how to switch from hydroxyurea to one of these therapies. Key topics and questions related to use of interferons, such as their safety and tolerability, the significance of variant allele frequency, advantages of early treatment, and what the future of interferon therapy may look like, will be examined. Pegylated interferons represent an important therapeutic option for patients with MPNs; however, more research is still required to further refine interferon therapy.

Advances in Risk Stratification and Treatment of Polycythemia Vera and Essential Thrombocythemia.

Estimating and modifying thrombotic risk is currently the mainstay of care for patients with polycythemia vera (PV) and essential thrombocythemia (ET). In recent years, however, increased attention has shifted towards quality of life and disease modification. In this review, we discuss recent advances in risk stratification, present updated results for ruxolitinib and interferon randomized clinical trials, discuss new approaches in antiplatelet and anticoagulant treatment, and summarize early phase trials of novel agents and emerging therapeutic concepts for the treatment of PV and ET. International collaborations and novel technologies, i.e., next-generation sequencing and machine learning techniques, have demonstrated excellent abilities to improve thrombotic risk stratification in PV and ET. Updated results from ruxolitinib and interferon randomized clinical trials have confirmed excellent efficacy and safety of these agents, both as first- and second-line treatments. Early trials of novel agents (histone deacetylase inhibitors, telomerase inhibitors, lysine-specific demethylase-1 inhibitors, human double-minute 2 inhibitors, and hepcidin mimetics) have shown encouraging efficacy and safety in blood count control, reduction of splenomegaly, and alleviation of disease-related symptoms. Finally, accumulating evidence suggested that direct oral anticoagulants may be a valid therapeutic alternative to warfarin for prolonged thromboprophylaxis. International collaborations ("big data") with the help of new technologies represent an exciting new approach to analyze rare outcomes in rare diseases, especially for identifying novel prognostic biomarkers in PV and ET. Randomized clinical trials are also needed to fully elucidate whether novel agents may establish new standards of care.

Chinese guideline for the diagnosis and treatment of polycythemia vera (2022)

Chinese guideline for the diagnosis and treatment of polycythemia vera (2022)

S196: ROPEGINTERFERON ALFA-2B ACHIEVES PATIENT-SPECIFIC TREATMENT GOALS IN POLYCYTHEMIA VERA: FINAL RESULTS FROM THE PROUD-PV/CONTINUATION-PV STUDIES

Background: Treatment of polycythemia vera (PV) aims to prevent thromboembolic complications, reduce the risk of progression to acute leukemia or myelofibrosis - of particular concern to patients - and ameliorate the symptom burden; specifically, to improve quality of life, therapy should address the most clinically important symptoms while reducing phlebotomies to avoid iron-deficiency symptoms. Long-term efficacy and safety of ropeginterferon alfa-2b have been demonstrated in PROUD-PV/CONTINUATION-PV; the final analysis applied a patient-focused approach. Aims: To analyze the patient-relevant benefit of ropeginterferon alfa-2b versus hydroxyurea (HU)/best available treatment (BAT) over 6 years. Methods: Patients diagnosed with PV according to WHO 2008 criteria who were cytoreduction-naïve or hydroxyurea pre-treated and gave written informed consent were randomized 1:1 to ropeginterferon alpha-2b or control treatment (HU) for one year in PROUD-PV. In CONTINUATION-PV, control arm patients could switch from HU to BAT. Patient-reported PV symptom burden was assessed based on adverse events documented in the patient diary and recorded at each visit; items defined in the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS; fatigue, concentration problems, early satiety, inactivity, night sweats, itching, bone pain, abdominal discomfort, weight loss, and fevers) and medical synonyms were evaluated post-hoc. Efficacy assessments included Kaplan-Meier analysis of event-free survival, phlebotomy need and JAK2V617F allele burden. Analyses were conducted on the CONTINUATION-PV full analysis set over 6 years of treatment. Results: The full analysis set comprised 95 patients in the ropeginterferon alfa-2b arm and 74 in the control arm. Patient-reported symptoms defined in the MPN-SAF TSS were present in a small minority (9.5%) of patients per arm at baseline (up to Week 4 of treatment) in this early-stage PV population. Occurrence of the defined symptoms remained low over long-term treatment, reported in 15.7% of patients in the ropeginterferon alfa-2b arm and 20.7% in the control arm during the 6th year of treatment. No phlebotomies were required to maintain hematocrit <45% in the 6th year of treatment in 81.4% of patients receiving ropeginterferon alfa-2b compared with 60.0% of patients in the control arm (p=0.005). Depletion of the JAK2V617F alle burden, which may lower the risk of progression to myelofibrosis, was observed in ropeginterferon alfa-2b treated patients; JAK2V617F allele burden <1% at 6 years was achieved in 19/92 (20.7%) patients in the ropeginterferon alfa-2b arm with baseline allele burden >10%. One patient met this threshold in the control arm (1/70 [1.4%]; p=0.0001). Event-free survival (risk events: disease progression, death and thromboembolic events) over ≥6 years of treatment was significantly higher among ropeginterferon alfa-2b treated patients than the control group (risk events reported in 5/95 vs. 12/74 patients, respectively; p=0.04 [Log-Rank]; Fig 1). Image:Summary/Conclusion: Long-term ropeginterferon alfa-2b therapy fulfils treatment goals important to patients with PV: a good quality of life as indicated by a low symptom burden and phlebotomy requirement, the potential to influence myelofibrosis risk, and better event-free survival versus BAT.

Bomedemstat tosylate. Lysine-specific demethylase 1 inhibitor, Treatment of essential thrombocythemia, Treatment of polycythemia vera, Treatment of myelofibrosis

Bomedemstat tosylate. Lysine-specific demethylase 1 inhibitor, Treatment of essential thrombocythemia, Treatment of polycythemia vera, Treatment of myelofibrosis

Normal Life Expectancy for Polycythemia Vera Patients Is Possible

▪Introduction: Polycythemia vera (PV), a chronic myeloproliferative neoplasm, is characterized by shortened overall survival (OS) due to potentially fatal thrombosis, progression to myelofibrosis (MF), and acute leukemia. Treatment with aspirin, attentive phlebotomy (PHL) and cytoreductive agents can prevent thrombosis; but it is unknown whether available treatments can achieve a normal life-span for PV patients (pts). Our objective was to assess the extent by which PV alters OS of pts receiving available treatment at our center and in the community.Methods: We obtained demographics and survival data of adult PV pts from our Weill Cornell Medicine (WCM) Research Database Repository (PV-WCM) diagnosed from 1974-2020 as previously described (Abu-Zeinah et al. Leukemia 2021); and from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program, 2001-2017. PV-WCM thrombosis and MF progression data were available. WCM institutional review board approval and SEER data use agreement were in place. OS of PV pts was estimated using Kaplan-Meier (KM) analysis. Propensity Score Matching was used to identify a subgroup of SEER pts (PV-SEER) with similar age, sex, and race demographics to PV-WCM for comparison of OS. Cox proportional hazards was used for multivariable analysis (MVA) of survival. Actuarial survival of the US population matched by age, sex, race, and year-of-birth was obtained from US Census. Observed OS was compared to actuarial OS using one-sided log-rank test.Results: We identified 470 PV-WCM and 16,492 PV pts from SEER. The median OS of the PV-WCM cohort and the SEER population was 26.6 and 12.8 years, respectively, but the groups differed by age and sex (Fig 1A). PV-WCM and matched PV-SEER, however, were well balanced by age, sex, and race (standardized mean difference <0.1). The median OS of PV-WCM was 10.8 years longer than PV-SEER (p<0.001, Fig 1B). MVA confirmed 65% lower mortality in the PV-WCM group relative to the PV-SEER population (p<0.001, Fig 1C). PV-SEER OS was shorter than actuarial OS of the US population (mortality HR 2.47, p<0.001), whereas PV-WCM OS was not significantly different than expected (mortality HR 1.15, p=0.136). Excess late mortality was observed in PV-WCM after 17 years, potentially due to increased incidence of MF progression, affecting almost 50% of PV pts after 25 years (Fig 1D).Discussion: These data point to the success of attentive management with aspirin, targeted PHL, and cytoreductive therapy at a specialty center in reducing the mortality of PV, owing in part, to ELN and NCCN treatment recommendations for preventing fatal thrombosis. Although excess thrombosis was not eliminated in PV-WCM pts, the incidence rate was low after the first two years (Fig 1D). In contrast, the incidence of MF progression increased, potentially contributing to excess late mortality. Current PV risk stratification and treatment recommendations neither predict nor aim to mitigate progression to MF, and do not satisfy the needs of younger, low-risk pts who are often symptomatic and harbor a lifetime threat of progression (Fig 1E). The recent Low-PV study showed that low-risk pts may also benefit from cytoreductive therapy with an agent such as interferon-alpha (rIFNα) over PHL alone (Barbui et al. Lancet Hematol 2021). PV-WCM pts treated with rIFNα (n=137), previously shown to have improved MF-free survival and OS (Abu-Zeinah et al. Leukemia 2021), had an OS similar to the matched US population (p=0.33, Fig 1F); whereas pts not treated with rIFNα had modestly shortened OS (HR 1.26, p=0.03). Because PV progression is among the leading causes of late morbidity and mortality, and available therapy can mitigate this, it may be time to reconsider and improve upon PV risk stratification and treatment.Conclusion: This large population-based and single center study shows that although PV survival remains shortened, normal life expectancy for PV pts is possible with available care. The discrepancy between survival in the community and at a specialized center highlights the need for greater community outreach, health equity, and education regarding treatment standards for PV. Hopefully, this study motivates development of new PV risk stratification and treatment recommendations that focus not only on hematologic control and thrombosis prevention, but also on preventing MF progression, improving OS, and restoring normal life expectancy. [Display omitted] DisclosuresAbu-Zeinah: PharmaEssentia: Membership on an entity's Board of Directors or advisory committees. Silver: Abbvie: Consultancy; PharamEssentia: Consultancy, Speakers Bureau. Scandura: CR&T (Foudation): Research Funding; European Leukemia net: Honoraria, Other: travel fees ; MPN-RF (Foundation): Research Funding; Constellation: Research Funding; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure:Interferon-alpha is used off label in the treatment of polycythemia vera.

Advances in the Treatment of Polycythemia Vera: Trends in Disease Management.

Treatment modalities for polycythemia vera (PV) have evolved over time. Phlebotomy and low-dose aspirin suffice in low-risk patients, but cytoreductive therapies are indicated in all high-risk patients (age ≥ 65 years or those with a history of PV-related thrombotic event) and may be considered for low-risk patients with progressively increasing splenomegaly, progressively increasing leucocyte and platelet counts, and for those who do not tolerate phlebotomy. Hydroxyurea/hydroxycarbamide or interferons can be used as first-line drugs. Hydroxyurea may not be tolerated by some patients, and it also carries risk of myelosuppression. Interferon alfa is especially useful for PV symptoms, and the newer preparation, ropeginterferon alfa-2b, has lesser incidence of flu-like reactions. Ruxolitinib reduces the JAK2V617F mutation burden and is used as a second-line drug. Anagrelide reduces platelet production and can be used in conjunction with hydroxyurea in patients with excessive thrombocytosis. The alkylating agent, busulfan, can also be used as a last resort in patients with a limited life expectancy. Prospective future treatments include givinostat, a histone deacetylase inhibitor, and idasanutlin, a murine double minute 2 antagonist.

Recent advances in prognostication and treatment of polycythemia vera.

Polycythemia vera (PV) is a BCR-ABL–negative myeloproliferative neoplasm marked by acquisition of an activating mutation of JAK2, which leads to not only erythrocytosis but also frequently to leukocytosis and thrombocytosis, and is associated with a high symptom burden and increased thrombotic risk. PV has the potential to progress to myelofibrosis or an aggressive form of acute myeloid leukemia. Mutational profiling of patients with PV has led to the development of risk stratification tools to determine an individual’s risk of developing progressive disease. Although the current goals of PV treatment are to alleviate symptoms and reduce thrombotic risk, there are growing efforts to identify disease-modifying agents which will also prevent progression of disease. Here, we give an overview of the developing prognostic tools and therapeutic landscape for PV, focusing on four drug classes: pegylated interferon-alpha 2, MDM2 antagonists, hepcidin mimetics, and histone deacetylase inhibitors.

A pharmacokinetic evaluation of ropeginterferon alfa-2b in the treatment of polycythemia vera

ABSTRACT Introduction Polycythemia vera (PV) is a Philadelphia chromosome-negative chronic myeloproliferative neoplasm (MPN). A newly developed PV treatment option, ropeginterferon alfa-2b, contains recombinant human alfa monoisomer as an active ingredient, resulting in a novel pharmacologic profile and improved tolerability. Efficacy studies conclude remarkable long-term hematological response and sustained JAK2V617F allele burden reduction. Ropeginterferon alfa-2b compound has been approved for the treatment of polycythemia vera without symptomatic splenomegaly. Areas covered Current clinical trials are investigating the role of ropeginterferon alfa-2b in the first-line setting of treatment for PV. The safety and efficacy results of completed trials are summarized in this review. Metabolic, pharmacokinetic issues are also discussed of ropeginterferon alfa-2b. Expert opinion Ropeginterferon alfa-2b is a targeted therapeutic option in the treatment of PV, representing a significant improvement compared to conventional cytoreductive therapies. The single isomer entity of the recombinant human interferon alfa-2b and the mono-pegylation method imparts favorable properties to the compound. The use of ropeginterferon alfa-2b allows extended dosing interval, reduces side effects, and may increase the overall survival of PV patients by reducing the risk of progression to myelofibrosis or acute leukemia. Clinical data suggests that the compound may provide a disease-modifying option for PV patients with asymptomatic splenomegaly.

Thrombosis and Bleeding as Presentation of COVID-19 Infection with Polycythemia Vera. A Case Report.

Coronavirus disease (COVID-19) has a wide spectrum of clinical manifestations. In this case report, we describe our first case of COVID-19 pneumonia that was complicated by cerebral venous thrombosis and bleeding in a patient with polycythemia vera. Madam A, a 72-year-old lady with polycythemia vera, ischemic stroke, hemorrhoids, diabetes mellitus, hypertension, and dyslipidemia was admitted to the hospital for COVID-19 pneumonia. She was treated with hydroxychloroquine and lopinavir/ritonavir as per hospital protocol. She continued taking hydroxyurea and aspirin for her treatment of polycythemia vera. Subsequently, she developed rectal bleeding when her platelet count was 1247 × 103/μl, even though she was not on an anticoagulant. Her aspirin was withheld. One week later, she was readmitted to the hospital for cerebral venous thrombosis and her D-dimer was 2.02 μg/ml. She was commenced on a therapeutic dose of low molecular weight heparin. Following that, her D-dimer level showed a decreasing trend and normalized upon her discharge. Patients with polycythemia vera are prone to develop thrombotic and bleeding complications. Management of this group of patients has become more complex with COVID-19 infection. It is crucial for us to decide when to start an anticoagulant especially when there is a history of recent bleeding. We need to balance the risks of further bleeding versus potentially fatal thrombotic events. Studies have shown that D-dimer can be used as a clinical marker to predict thrombotic events in COVID-19 infection. Patients with COVID-19 infection and polycythemia vera will benefit from both pharmacological thromboprophylaxis and close monitoring for bleeding.

Novel approaches to the treatment of polycythemia vera

Novel approaches to the treatment of polycythemia vera

Recent advances in polycythemia vera treatment

Since the discovery of the gain-of-function mutation JAK2 V617F, significant progress has been made in clarifying the pathology and developing novel agents for myeloproliferative neoplasms, including polycythemia vera (PV). The treatment strategy for PV is to first classify patients into either high- or low-risk groups for thrombosis. All patients with PV should be treated with low-dose aspirin and phlebotomy. In addition, for high-risk PV patients, cytoreductive therapy is recommended. Although hydroxyurea (HU) is the most popular agent for PV treatment, the advantages of ruxolitinib, a JAK inhibitor, for patients who are intolerant or resistant to HU were recently reported. Furthermore, the ability of interferon-α to selectively eliminate the malignant clone and induce complete molecular response was previously demonstrated. In this article, important clinical trials associated with the treatment strategy for PV and recent advances in PV treatments are described.

Superiority of IFN Versus HU Using a Novel Biomarker-Based Tool for Assessment of Disease Burden in MPNs

Background: Treatment of polycythemia vera (PV) patients with hydroxyurea (HU) normalizes elevated blood cell counts within weeks in the large majority of patients. Studies on the impact of HU upon the kinetics of the JAK2V617F allele burden, leukocyte and platelets over time are scarce, and results have been reported highly heterogeneous. Purpose: Using data driven analysis as a novel tool to model the kinetics of the JAK2V617F allele burden and blood cell counts over time during treatment with HU. Material and Methods: Using serial measurements of JAK2V617F and correlation analyzes of routine hematological values (Hb-concentration, leukocyte count, platelet count, lactic dehydrogenase), we present a detailed description and analysis of the kinetics of the JAK2V617F, leukocyte and platelet counts and lactic dehydrogenase in 29 PV patients who were followed in the Danish randomized trial (DALIAH) comparing the efficacy of pegylated interferon-alpha2 (IFN) versus HU in patients older than 60 years. Results: Response patterns were highly heterogeneous. In the large majority of patients, HU treatment was initially associated with a modest decline in the JAK2V617F allele burden in concert with a decline in leukocyte and platelet counts. However, HU did not induce a sustained and continuous decrease in the JAK2V617F allele burden in any patient as previously reported in patients being treated with IFN. Importantly, HU treatment was neither able to induce a sustained normalization of elevated leukocyte and platelet counts, although counts were temporarily normalized in most patients during the first months of therapy. The fluctuating leukocyte and platelet counts contrast the sustained normalization of cell counts in the large majority of patients during long term treatment with IFN. Discussion and Conclusions: Using data-driven analysis of the JAK2V617F allele burden, leukocyte and platelet kinetics during treatment with HU, we have shown that HU does not induce a sustained decrease in the JAK2V617F allele burden and neither induces sustained normalization of elevated cell counts in PV patients. Our results may explain why PV patients during treatment with HU still have a substantially increased risk of thrombosis. Based upon our previous and present findings, obtained by mathematical modelling and data driven analysis studies, a rational and cost-effective treatment might be a combination therapy of HU and IFN, both being used for decades in the treatment of PV but according to the findings in our studies now being proposed to be combined in the initial treatment period, since their combined effects might be highly efficacious and are foreseen to have the potential to minimize the risk of thrombosis and bleeding. By these studies, we have also proven mathematical modelling and data driven analysis to be highly important tools to decipher novel treatment modalities for patients suffering from MPN cancers but likely other cancers as well. Disclosures Hasselbalch: Novartis: Research Funding; AOP Orphan Pharmaceuticals: Other: Data monitoring board. OffLabel Disclosure: Interferon-alpha2 for the treatment of myeloproliferative neoplasms.

Expansion of Prior Existing TP53 Mutated Clones in Polycythemia Vera Patients Treated with Idasanutlin

Expansion of Prior Existing TP53 Mutated Clones in Polycythemia Vera Patients Treated with Idasanutlin

Clinical outcomes under hydroxyurea treatment in polycythemia vera: a systematic review and meta-analysis.

Hydroxyurea is the standard treatment in high-risk patients with polycythemia vera. However, estimates of its effect in terms of clinical outcomes (thrombosis, bleeding, hematologic transformations and mortality) are lacking. We performed a meta-analysis to determine the absolute risk of events in recent cases of patients under hydroxyurea treatment. We searched for relevant articles or abstracts in the following databases: Medline, EMBASE, clinicaltrials.gov, WHO International Clinical Trials Registry, LILACS. Sixteen studies published from 2008 to 2018 reporting number of events using World Health Organization diagnosis for polycythemia vera were selected. Through a random effect logistic model, incidences, study heterogeneity and confounder effects were estimated for each outcome at different follow ups. Overall, 3,236 patients were analyzed. While incidences of thrombosis and acute myeloid leukemia were stable over time, mortality and myelofibrosis varied depending on follow-up duration. Thrombosis rates were 1.9%, 3.6% and 6.8% persons/year at median ages 60, 70 and 80 years, respectively. Higher incidence of arterial events was predicted by previous cardiovascular complication. Leukemic transformation incidence was 0.4% persons/year. Incidence of transformation to myelofibrosis and mortality were significantly dependent on age and follow-up duration. For myelofibrosis, rates were 5.0 at five years and 33.7% at ten years; overall mortality was 12.6% and 56.2% at five and ten years, respectively. In conclusion, we provide reliable risk estimates for the main outcomes in polycythemia vera patients under hydroxyurea treatment. These findings can help design comparative clinical trials with new cytoreductive drugs and prove the feasibility of using critical end points for efficacy, such as major thrombosis.